vochindik: The way I learned it is that some believe that the a lot of the provisions in tzava’ah was really intended only for R’ Yehudah’s descendants – being that he saw with ruach hakodesh (or something like that) that these specific scenarios would not play out well for his descendants. According to that opinion, it has nothing to do with R’ Yehudah HaChosid paskening for general application.
